SU679604A1 - Vulcanisable polymeric composition - Google Patents

Description

one

The invention relates to polyethylene-based polymeric materials and can be used to protect equipment from exposure to aggressive media.

Vulcanizable polyethylene compositions based on polyethylene are known, which contain various peroxide compounds as a vulcanizing agent, for example dicumyl peroxide, and a heat stabilizer 1.: These compositions have an unsatisfactory degree of vulcanization, which reduces their physicomechanical properties.

Closest to the proposed technical essence and the achieved effect is a vulcanizable polymer composition based on polyethylene, containing a vulcanizing agent — dicumyl peroxide, a heat stabilizer — Santonox R, an activator of decomposing a vulcanizing agent — trigshylthiophosphate 2

This composition also has an insufficient degree of vulcanization, since the santonox R stabilizer causes a radically free decomposition of the vulcanizing agent.

The aim of the invention is to increase the degree of vulcanization.

This goal is achieved in that a polyethylene-based composition containing a vulcanizing agent, an activator and a heat stabilizer contains isopropylbenzene hydroperoxide as a vulcanizing agent, ferrous sulfate as an activating agent,

0 heat stabilizer - polyanilindisulfide, in the following ratio of components, wt.%

Polyethylene91,5-98,4

five

Hydroperoxide

isopropylbenzene 1-6 Ferrous sulphate, 0 Poly nylindisulfide 0.1-1.5 Ferrous sulphate increases 0 the rate of decomposition of isopropylbenzene hydroperoxide into radicals, which contributes to an increase in the vulcanization depth.

five

Polyanilindisulfide not only increases the heat resistance of the composition, but, unlike santonox R, contributes to the reflux of iron sulfate, radical reduction, and hydroperoxide decomposition.

0 isopropylbenzene, which also increases the depth of vulcanization (see tab.2,

got 11).

Example. Prepare the composition as follows. The components are loaded into the Henshel mixer in the following sequence: powdered polyethylene, isopropyl benzene hydroperoxide, ferrous sulfate

and polyaniline disulfide. Mix the mixture for 1 hour.

The resulting mixture is subjected to vulcanization at 170-180 C for 20 minutes

5 The compositions of vulcanizing compositions are given in table 1.

Table 1 .

98.4 95.5 91.5

98.4 95.5 91.5 To estimate the degree of vulcanization, the compositions determine the content of the gel fraction by the amount of insoluble residue on a hot filter funnel obtained after boiling a portion of the vulcanizing composition in xylene for 1 hour.

Strength characteristics are determined according to GOST 11262-68: plates are pressed from a vulcanizing composition on a hydraulic press, then the blades are cut down from the plates and the tensile strength is determined on an RMI-60 tensile machine. The test results are shown in Table 2.

95.5 96.0

98.4 95.5 91.5

Table 2

Offered

89 138 525

97 165 490

94 157 503

87 225 535

96,265,510

Continued table. 2

93 85 97 94

242

517 234 485 285 456 262 472

Known

85. 207 535 Y4 unstabilized 205 547

From the analysis of the data obtained it can be seen that the optimum content in the composition of hydroperoxide isopropyl benzene is 3%, ferrous sulfate 1%, polyanylindisulfide 0.5%. At the same time, compared with the known, the depth of vulcanization of the composition increases6796046

from 85 to 96-97%, and the strength at break increases by 28-38%.

Claims (2)

1. Fettes E. Chemical reactions 25: examples m., World, 1967, v.1, p.168. 2.Sirota A.G. Modification of the structure and properties of polyolefins, L., Hilsch, 1974, p. 159.